He almost certainly does NOT appreciate or realize how lucky he is, and probably should not be expected to. Particularly with kids in a demographic where many of their peers are similarly privileged, it's really all they know. I have struggled with this for years; my kids are in an independent (Montessori) school, and while there is certainly some variation in financial circumstances across families, the vast majority are upper middle class, two professional working parent families. Private school education, nice house in a good neighbourhood, all-you-can-eat sports and other extra-curricular activities, nice vacations - all this is "normal" for them, because it's what they see both in our home and those of their peers. I was raised in very different circumstances, and I would love for my kids to recognize that most of the world does not live this way. But short of deliberately changing our entire lifestyle just to make that point, I've never figured out how to do this effectively.
Well, maybe.

But I live in hope that with age and perspective, they will eventually come to realize how fortunate they are. They may appear to be ungrateful and self-entitled now, but that doesn't necessarily mean they will turn out to be ungrateful and self-entitled adults.
(
@HappilyEverAfter80, please know that I quoted your post because it gave me an opportunity to speak of my own experience; I'm not at all intending to pass judgement or offer advice on your parenting choices!)
As to the more general topic of the thread, this is one reason (of many) why I don't try to surprise my kids with vacations. I usually make them part of the planning process. That doesn't mean they get to dictate where we go and what we do, but their input is considered. We all enjoy WDW, but as parents we mostly enjoy it because the kids enjoy it. And while there are things about
DCL that we appreciate as adults, I don't know that it would be our first choice if we were travelling without kids. So if they don't really want to do WDW or DCL, we'll do something else instead. So many interesting places to visit, so little time!